--- a/dom/media/fmp4/MP4Demuxer.cpp
+++ b/dom/media/fmp4/MP4Demuxer.cpp
@@ -52,16 +52,18 @@ public:
 
   RefPtr<SkipAccessPointPromise>
   SkipToNextRandomAccessPoint(const media::TimeUnit& aTimeThreshold) override;
 
   media::TimeIntervals GetBuffered() override;
 
   void BreakCycles() override;
 
+  void NotifyDataRemoved();
+
 private:
   friend class MP4Demuxer;
   void NotifyDataArrived();
   already_AddRefed<MediaRawData> GetNextSample();
   void EnsureUpToDateIndex();
   void SetNextKeyFrameTime();
   RefPtr<MP4Demuxer> mParent;
   RefPtr<mp4_demuxer::ResourceStream> mStream;
@@ -323,20 +325,20 @@ MP4Demuxer::NotifyDataArrived()
     dmx->NotifyDataArrived();
   }
 }
 
 void
 MP4Demuxer::NotifyDataRemoved()
 {
   for (auto& dmx : mAudioDemuxers) {
-    dmx->NotifyDataArrived();
+    dmx->NotifyDataRemoved();
   }
   for (auto& dmx : mVideoDemuxers) {
-    dmx->NotifyDataArrived();
+    dmx->NotifyDataRemoved();
   }
 }
 
 UniquePtr<EncryptionInfo>
 MP4Demuxer::GetCrypto()
 {
   UniquePtr<EncryptionInfo> crypto;
   if (!mCryptoInitData.IsEmpty()) {
@@ -606,16 +608,29 @@ MP4TrackDemuxer::GetBuffered()
 
 void
 MP4TrackDemuxer::NotifyDataArrived()
 {
   mNeedReIndex = true;
 }
 
 void
+MP4TrackDemuxer::NotifyDataRemoved()
+{
+  AutoPinned<MediaResource> resource(mParent->mResource);
+  MediaByteRangeSet byteRanges;
+  nsresult rv = resource->GetCachedRanges(byteRanges);
+  if (NS_FAILED(rv)) {
+    return;
+  }
+  mIndex->UpdateMoofIndex(byteRanges, true /* can evict */);
+  mNeedReIndex = false;
+}
+
+void
 MP4TrackDemuxer::BreakCycles()
 {
   mParent = nullptr;
 }
 
 } // namespace mozilla
 
 #undef LOG